$49g^2\:+\:56gh\:+\:16h^2$

$\left(x-2\right)^3-\left(x+5\right)^3+7-21x^2$

$+83-\left(+63\right)-\left(+51\right)-\left(-85\right)-\left(+43\right)$

$-15\cdot\left(-4\right)+2\cdot\left(-3\left(2\right)\right)+\left(6-2\left(8\right)\right)$

$\int6^{4x}dx$

$-2.5y\:+\:8y\:-\:10.5y$

$x^2-\frac{2}{x+1}$